It's really down to prosperity. A society has to have attained a certain level of prosperity before many people can afford to build in a way that will last. Before that point, castles and churches might be built out of stone, but virtually everything else is jerry-built, and falls down or, if it is damaged, is not considered worth repairing. So buildings are constantly replaced by newer builldings on the same site, and you have few or no suriviving private residences or commercial buildings from the period.
England basically reached this level of prosperity during the Tudor era, so from that point on they were building enough durable houses, etc, that some of them have lasted. So, say, from the early sixteenth century. Ireland didn't get there until the late seventeenth. Whereas if you go to, say, Italy, they got there well before England so you have plenty of houses, villas, etc from the fifteenth century or before.